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Active Calculus - Multivariable

Activity 11.1.4.
In the following activity, we investigate the use of traces to better understand a function through both tables and graphs.
(a)
Identify the \(y = 0.6\) trace for the distance function \(f\) defined by \(f(x,y) = \frac{x^2 \sin(2y)}{g}\) by highlighting or circling the appropriate cells in Table 11.1.10. Write a sentence to describe the behavior of the function along this trace.
(b)
Identify the \(x = 150\) trace for the distance function by highlighting or circling the appropriate cells in Table 11.1.10. Write a sentence to describe the behavior of the function along this trace.
(c)
In the next several tasks, we will be looking at using traces to help us draw an accurate plot of the surface given by \(z=g(x,y)=yx^2\text{.}\) For our first task, find the equation for the \(y=1\) trace of \(z=g(x,y)=yx^2\) and draw a graph of the \(y=1\) trace on the corresponding face in Figure 11.1.17.
Figure 11.1.17. A bounding box for the region with \(-1 \leq x,y,z \leq 1\)
(d)
Find the equation for each of the following traces and draw a plot of the trace on the corresponding face in Figure 11.1.17.
  • \(\displaystyle y=-1\)
  • \(\displaystyle x=1\)
  • \(\displaystyle x=-1\)
(e)
Draw a few traces (at least three more) that correspond to values in the middle of the plot to fill in a plot of the surface given by \(z=x^2y\text{.}\)